The present disclosure relates to an optical device suited for illuminating a linear or quadrangular area, and a lighting device using the same.
Japanese Patent Publication No. 2012-074278 discloses a lighting device capable of achieving a long linear irradiation range using a small number of light source modules. The lighting device disclosed in this patent publication is equipped with light source units arranged in two rows, four units per row. Each light source unit comprises a set of light source modules. Each light source module distributes the divergent beams of light from the light emitting element into first outgoing light forward of the substrate via the light source lens and second outgoing light forward of the substrate after being refracted by the light source lens and reflected by the second reflectors. In each light source unit, two light source modules are disposed back to back so that their substrates form an acute angle, allowing the light source unit to spread the light at the angle formed by the substrate of one of the light source modules and the substrate of the other light source module to thereby produce linear illumination light having a constant width. The lighting device can thus achieve a long linear irradiation range.